Half to william evans



' less.

NITED STATES PATENT OFFICE.

HENRY HOLMES, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE- HALF TO WILLIAM EVANS, OF SAME PLACE.

LIQUID COMPOSITION OF MATTER FOR TREATING HIDES QR SKINS.

SPECIFICATION forming part of Letters Patent No. 615,705, dated December 13, 1898.

' Application filed July 24, 1897. Serial No. 645,782. (No specimensl) To all whom it may concern.-

Be it known that I, HENRY HOLMES, a citizen of the United States, residing at the city of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Liquid Compositions of Matter for Treating Hides or Skins, of which the following is a specification.

My invention has relation to a liquid composition of matter adapted to treat hides or skins in a state or condition known as raw stock and to prepare the same for the tanning operation by swelling the fiber, softening the gristle, and dissolving the animal and other refuse matters therefrom.

My invention consists of a liquid composition of matter for treating hides or skins in the raw state composed of asolution of sodium sulfid having in suspension a demulcent, such as chalk or whiting, the composition comprising a bath wherein the hides or skins are immersed and agitated, as hereinafter described.

llly composition consists of the following ingredients in about the proportions stated, viz: sodium sulfid, three parts chalk or whiting, one part, and water in sufficient quantity say eight gallons, more or less.

The sodium sulfid, in quantity about three ordinary bucketsful, is first dissolved in Water to obtain a solution of a strength varying from 2 to 6 Baum test, more [or less, the strength varying with the nature of the hides or skins to be treated.

The demulcent which I use is chalk or whiting, the same being used with Water in suflicient quantity, say eight gallons, more or less, to mix with, say, one ordinary bucketful of the demulcent. This mixture is then added to the previously-prepared sodium-sulfid solution. The solution, with the demulcent in suspension, is then introduced into an open vat or vessel provided with means for mechanically agitating the same. The hides or skins are now introduced into this solution, which latter is thoroughly agitated for a short period of time, say for two hours, more or The hides or skins are then permitted to remain at rest in the solution for a comparatively long period of time, say ten to twelve hours, more or less, when the solution is again agitated. Duringthe second agitation the solution is gradually diluted by the addition of fresh water until it contains no matter in solution or suspension, but is substantially free of the same.

I am aware, as described in my Letters Pat ent No. 593,660, dated November 16, 1897, that it has been proposed to treat hides or skins for preparing them for the tanning operation with a solution of sodium sulfid and water. and that such will accomplish results provided the nature and character of the skins to be treated can be accurately ascertained; but in the practice of using the dissolved sodium sulfid it has been found that the caustic nature of the sulfid will act more vigorously on some hides or skins than on others, thus burning the skins and contracting the grain and depleting the hide or skin of its gelatinous or glutinous substances.

I am also aware that it has been proposed to use as a depilatory agent a sodium-sulfid solution containing lime, lime and arsenic, and pipe-clay; but in practice such materials or substances added to said solution are used solely to depilate or remove the hair and cannot be used for the purpose of preparing the skin for the tanning operation, since these agents will roughen and harden the grain of the skin, impoverish the fiber, and cause a harshness as well as dryness of the skin, and the skin cannot without further manipulation be tanned into leather.

By mixing with the sulfid-of-sodium solution a demulcent, such as chalk or whiting, a liquid compound is provided, in the use of which the caustic nature of the sulfid is mollified and made far less energetic in its action upon the gelatinous or glutinous substances of the hides or skins. By reason of its mild chemical action the liquid readily softens the gristle, swells the fiber, as Well as effects speedy dissolution of such animal matter as it is desirable to remove. The skin when treated according to my invention, as hereinbefore described, is ready for the tanning operation without further manipulation or treatment and when tanned has a fine smooth grain and a firm, plump, and mellow feel.

Having thus described the nature and ob jectof my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A liquid compound for treating hides and skins in their raw state to prepare them for the immediate and subsequent tanning operation Without further manipulation or treatment, said compound, comprising a solution of sulfid of sodium and a demulcent such as chalk or whiting held in suspension in said solution, substantially as described.

2. A liquid compound or bath for treating hides and skins in their raw state so as to swell the fiber, soften the gristle and dissolve animal and refuse matters therefrom to prepare them for the subsequent tanning opera tion without further manipulation or treatment, said compound or bath, comprising a solution of sulfid of sodium of required 

